Amyloidosis as an Atypical Cause of Biliary Stricture Diagnosed by Cholangioscopy.

Amyloidosis is a rare cause of common bile duct (CBD) stricture that often presents with nonspecific symptoms. We herein report the case of a 61-year-old woman with CBD stricture caused by amyloidosis diagnosed through cholangioscopy and confirmed by a biopsy, with subsequent findings identifying it as AA-type amyloidosis. This condition poses diagnostic challenges owing to its rarity and non-specific manifestations. When common causes are excluded, amyloidosis should be considered in the differential diagnosis of CBD stricture. Advanced imaging and cholangioscopy with targeted biopsies are essential for making an accurate diagnosis. Documenting such cases and further research are vital to improve the understanding and management of amyloidosis-related biliary stricture.